The correct option is D 3.3 billion
Human genome has around 21,000 genes in its 3.3 billion base pairs haploid genome. The haploid DNA content of a cell is called as C-value. The C-value paradox is concerned with presence of excessive amounts of DNA in eukaryotic cells and the difference of C-value between eukaryotic species having similar complexity. Presence of large amount of base pairs is explained on the basis of large amount of structural DNA and junk DNA in chromosomes. Thus, correct answer is '3.3 billion'.